What is Solar Power
What is solar power?
Solar power is power generated from sunlight. Solar power can be used to generate electricity, provide hot water, and to heat, cool and light buildings. Contrary to popular belief, solar power systems are ideal for UK conditions, including in the North East of England. The systems do not need bright sunshine to operate as solar radiation consists of two components direct sunlight (sunny weather) and diffuse sunlight (cloudy weather). Systems work in both conditions using the suns energy.
Solar energy can be captured by solar panels. There are 2 main types of solar panels which use different technologies to make use of the energy from the sun:
- Solar Water Heating collectors (or solar hot water or solar thermal), which absorb the energy from the sun and use it to heat water to provide hot water
- Photovoltaic panels (or solar cell or solar electric panels), which transform the solar radiation directly into electricity.
Solar water heating
Solar thermal technology is one of the most efficient and immediately accessible utilisation of renewable energy available in the UK today. Solar thermal heating systems consist of a collector (which fits easily onto most roofs), a storage tank, and a simple water pump. The system's simplicity guarantees its reliability - there are few moving parts and no complex, experimental technology that may fail a householder at a time of need. The systems have been installed across Europe for decades. A collector absorbs the sun’s power and heats fluid in tubes which is then pumped or moved to the storage tank where water can be heated. The systems also use a 'drainback' principle, which virtually eliminates the risk of water freezing in the system. Solar water heating systems can provide over half of a household's hot water requirements over the year. An average system presently costs around £2,500, but with a Clear Skies grant of around £400, this comes down to around £2,100. Given the average cost per annum of heating domestic hot water (usually £400-£500), an average system could pay for itself in 4 - 5 years.
Photovoltaics (PVs)
PV systems convert sunlight directly into electricity. A solar or PV cell is made up of semiconducting material that absorbs the sunlight. The solar energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity. PV cells are commonplace in many everyday applications e.g. calculators and watches, and are increasingly being used for domestic and larger applications where they are roof mounted or integrated into buildings to generate electricity. For building use, PV cells are typically combined into modules that hold about 40 cells. Around 10 of these modules are then mounted in PV ‘arrays’, which can be used to generate electricity for a single building or, in large numbers, for a power plant. A power plant can also use a Concentrating Solar Power System, which uses the sun’s heat to generate electricity. The sunlight is collected and focused with mirrors to create a high-intensity heat source. The cost of PVs have fallen by 90% since the early 1970s, and will continue to do so as volume production lowers manufacturting costs.
Passive solar
It is also possible to use the sun's energy more efficiently using passive measures, by applying good design measures. The use of passive solar design is possibly the simplest form of solar energy. Many buildings today are designed to utilise the energy of the sun as efficiently as possible. The location and orientation of the building are all key factors in optimising passive solar design. Passive solar design can be best applied in new buildings, where the orientation of the building, the size and position of the glazed areas, the density of buildings within an area, and materials used for the remainder of the structure are designed to maximise free solar gains. Designing a property to maximise free solar gain need not add to the price of construction.